Solid-state imaging apparatus and driving method thereof

ABSTRACT

The present technology relates to a solid-state imaging apparatus and a driving method that can perform imaging at lower power consumption. 
     By providing the solid-state imaging apparatus including a pixel array section on which a plurality of SPAD pixels is two-dimensionally arranged, in which in a case where illuminance becomes first illuminance higher than reference illuminance, a part of the SPAD pixels of the plurality of pixels arranged on the pixel array section is thinned, it is possible to image at lower power consumption. The present technology can be applied to an image sensor, for example.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a Continuation Application of U.S. patentapplication Ser. No. 16/479,843 filed Jul. 22, 2019, which is a 371National Stage Entry of International Application No.:PCT/JP2018/029162, filed on Aug. 3, 2018, which in turn claims priorityfrom Japanese Application No. 2017-156746, filed on Aug. 15, 2017, theentire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present technology relates to a solid-state imaging apparatus and adriving method thereof and, more particularly to, a solid-state imagingapparatus and a driving method thereof such that imaging can beperformed with lower power consumption.

BACKGROUND ART

An SPAD (Single Photon Avalanche Diode) that is a photodiode technologyhaving read-out sensitivity at one photon level by electronicmultiplication (for example, see Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: US 2015/0054111 A1

DISCLOSURE OF INVENTION Technical Problem

Incidentally, the SPAD has a structure of an Avalanche section in asemiconductor so as to detect one photon, through which an electronphotoelectrically converted from one photon passes, and the electron ismultiplied tens of thousands times. Thus, the solid-state imagingapparatus using the SPAD pixels is suitable for imaging at a dark scenewith a small amount of light.

On the other hand, in a case where the solid-state imaging apparatususing the SPAD pixels is used for imaging at a bright scene with a largeamount of light, tens of thousands of photons are incident andmultiplied, and hundreds of millions of electrons are generated. As aresult, consumption power becomes extremely great, and it is thereforedesirable to reduce the consumption power.

The present technology is made in view of the above-mentionedcircumstances, and it is an object of the present technology to providea solid-state imaging apparatus using SPAD pixels that can performimaging at lower power consumption.

Solution to Problem

According to an aspect of the present technology, a solid-state imagingapparatus includes a pixel array section on which a plurality of SPAD(Single Photon Avalanche Diode) pixels is two-dimensionally arranged, inwhich in a case where illuminance becomes first illuminance higher thanreference illuminance, a part of the SPAD pixels of the plurality ofpixels arranged on the pixel array section is thinned.

According to an aspect of the present technology, a driving method of asolid-state imaging apparatus including a pixel array section on which aplurality of SPAD pixels is two-dimensionally arranged includes in acase where illuminance becomes first illuminance higher than referenceilluminance, thinning a part of the SPAD pixels of the plurality ofpixels arranged on the pixel array section.

In the solid-state imaging apparatus and the driving method according toan aspect of the present technology, in a case where illuminance becomesfirst illuminance higher than reference illuminance, thinning a part ofthe SPAD pixels of the plurality of pixels arranged on the pixel arraysection

The solid-state imaging apparatus according to an aspect of the presenttechnology may be an independent apparatus or may be an internal blockconfiguring one apparatus.

Advantageous Effects of Invention

According to an aspect of the present technology, it is possible toimage at lower power consumption.

It should be noted that the effects described here are not necessarilylimitative and may be any of effects described in the presentdisclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration example of anembodiment of a solid-state imaging apparatus to which the presenttechnology is applied.

FIG. 2 is a diagram showing a first example of driving a plurality ofSPAD pixels arranged on a pixel array section.

FIG. 3 is a diagram showing a second example of driving a plurality ofSPAD pixels arranged on a pixel array section.

FIG. 4 is a cross-sectional view showing a first example of a structureof the SPAD pixel.

FIG. 5 is a cross-sectional view showing a second example of a structureof the SPAD pixel.

FIG. 6 is a plan view showing a third example of a structure of the SPADpixel.

FIG. 7 is a cross-sectional view showing a third example of a structureof the SPAD pixel.

FIG. 8 is a plan view showing a fourth example of a structure of theSPAD pixel.

FIG. 9 is a cross-sectional view showing a fourth example of a structureof the SPAD pixel.

FIG. 10 is a diagram showing an example of an Avalanche probability by avoltage difference between an anode and a cathode of the SPAD.

FIG. 11 is a flowchart of explaining a flow of SPAD pixel drivingcontrol processing.

FIG. 12 is a plan view showing other example of a structure of the SPADpixel.

FIG. 13 is a plan view showing other example of a structure of the SPADpixel.

FIG. 14 is a block diagram showing a configuration example of anelectronic device including the solid-state imaging apparatus to whichthe present technology is applied.

FIG. 15 is a diagram showing a usage example of the solid-state imagingapparatus to which the present technology is applied.

FIG. 16 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 17 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present disclosure will be describedwith reference to the drawings.

The embodiments of the present technology will be described in thefollowing order.

1. Configuration of solid-state imaging apparatus

2. Embodiments of the present technology

3. Modifications

4. Configuration of electronic device

5. Usage example of solid-state imaging apparatus

6. Application example for mobile body

<1. Configuration of Solid-State Imaging Apparatus>

(Configuration Example of Solid-State Imaging Apparatus)

FIG. 1 is a block diagram showing a configuration example of anembodiment of a solid-state imaging apparatus to which the presenttechnology is applied.

A solid-state imaging apparatus 10 is an image sensor that receivesincoming light from an object to be imaged, converting an amount of theincoming light imaged on an imaging surface into an electric signal foreach pixel unit, and outputting it as a pixel signal.

In FIG. 1, the solid-state imaging apparatus 10 includes a pixel arraysection 21, a control circuit 22, and a readout circuit 23.

In the pixel array section 21, a plurality of SPAD (Single PhotonAvalanche Diode) pixels is two-dimensionally (matrix) arranged. Here,the SPAD pixel is a pixel including a single photon Avalanche photodiode(SPAD). This single photon Avalanche photodiode has a structure of anAvalanche section in a semiconductor so as to detect one photon, throughwhich an electron photoelectrically converted from one photon passes,and the electron is multiplied (amplified) tens of thousands times.

The control circuit 22 controls an operation of each section of thesolid-state imaging apparatus 10.

In addition, the control circuit 22 outputs a control signal (pulse) fordriving the SPAD pixels via a pixel driving line, to thereby controllingthe driving of the plurality of SPAD pixels two-dimensionally arrangedon the pixel array section 21. For example, the control circuit 22controls the driving of the plurality of SPAD pixels two-dimensionallyarranged on the pixel array section 21 on the basis of a detectionresult of illuminance.

The readout circuit 23 successively scans the plurality of SPAD pixelstwo-dimensionally arranged on the pixel array section 21 and reads outthe pixel signal generated by each SPAD pixel via a signal line. Thereadout circuit 23 outputs the read out pixel signal to a signalprocessing section (not shown) at a latter part.

The solid-state imaging apparatus 10 is configured as described above.

<2. Embodiments of the Present Technology>

Incidentally, the solid-state imaging apparatus 10 has the pixel arraysection 21 on which the plurality of SPAD pixels two-dimensionallyarranged. At the time of imaging in a bright place, tens of thousands ofphotons are incident and multiplied, for example, to thereby generatinghundreds of millions of electrons. Therefore, it is desirable to reduceconsumption power. According to the present technology, the consumptionpower is reduced by the following methods.

Specifically, in the solid-state imaging apparatus 10, in a case whereilluminance is higher than reference illuminance, a part of the SPADpixels are thinned from the plurality of SPAD pixels arranged on thepixel array section 21. Thus, imaging can be performed at lower powerconsumption.

Note that illuminance can be classified into three stages of highilluminance, medium illuminance lower than the high illuminance, and lowilluminance lower than the medium illuminance, for example, depending ona threshold value. Specifically, for example, the high illuminance isset to about 10,000 lux, the medium illuminance is set to about 1,000lux, and the low illuminance is set to about 0.01 lux.

Also, for example, the illuminance can be classified into two stages ofthe high illuminance and the low illuminance lower than the highilluminance, for example, depending on the threshold value. In otherwords, the illuminance is classified into plural stages of illuminancedepending on the threshold value.

First Example of Driving SPAD Pixels

FIG. 2 shows a first example of driving the plurality of SPAD pixelsarranged on the pixel array section 21 of FIG. 1.

FIG. 2 shows pixels in 16 rows and 16 columns arranged at an upper leftregion seen, for example, from a light incident side among a pluralityof SPAD pixels 100 two-dimensionally arranged on the pixel array section21.

Note that each row number and each column number corresponding to i rowand j column of the SPAD pixels 100 are denoted at a left side regionand an upper side region in FIG. 2. In the following description, the irow and the j column of the plurality of SPAD pixels 100 arranged on thepixel array section 21 denote the SPAD pixel 100 (i, j).

In addition, as a color filter, a red (R) color filter is arranged. Thepixel that receives the pixel signal corresponding to light of a red (R)component from the light transmitted through the R color filter isdenoted as an R pixel.

Similarly, the pixel that receives the pixel signal corresponding tolight of a green (G) component from the light transmitted through agreen (G) color filter is denoted as a G pixel. Also, the pixel thatreceives the pixel signal corresponding to light of a blue (B) componentfrom the light transmitted through a blue (B) color filter is denoted asa B pixel.

Specifically, in the pixel array section 21, the plurality of SPADpixels 100 is two-dimensionally and regularly arranged as the R pixels,the G pixels, or the B pixels to form a Bayer array. Note that the Bayerarray is an arrangement pattern that the G pixels are arranged in acheckered pattern and the R pixels and the B pixels are arrangedalternately for one column in the remaining parts.

Here, in the pixel array section 21, a SPAD pixel 100 (3, 3) is looked.This SPAD pixel 100 (3, 3) is the B pixel and also a thinned pixel towhich a letter “OFF” is added.

The thinned pixels are pixels thinning among a plurality of SPAD pixels100 two-dimensionally arranged on the pixel array section 21 at the timeof the high illuminance. The SPAD pixel 100 (3, 3) becomes the thinnedpixel in accordance with a driving control from the control circuit 22at the time of the high illuminance.

In the pixel array section 21, a SPAD 100 (2, 9), a SPAD pixel 100 (4,7), a SPAD pixel 100 (4, 13), a SPAD pixel 100 (6, 2), a SPAD pixel 100(6, 7), a SPAD pixel 100 (6, 14), a SPAD pixel 100 (7, 13), and a SPADpixel 100 (8, 5) are set to the thinned pixels similar to the SPAD pixel100 (3, 3).

Furthermore, in the pixel array section 21, a SPAD pixel 100 (9, 16), aSPAD pixel 100 (10, 4), a SPAD pixel 100 (10, 13), a SPAD pixel 100 (11,1), a SPAD pixel 100 (11, 5), a SPAD pixel 100 (11, 9), a SPAD pixel 100(13, 3), a SPAD pixel 100 (13, 13), a SPAD pixel 100 (14, 6), a SPADpixel 100 (14, 9), and a SPAD pixel 100 (15, 15) are set to the thinnedpixels similar to the SPAD pixel 100 (3, 3).

Thus, in the pixel array section 21, any SPAD pixels 100 among theplurality of SPAD pixels 100 are set to the thinned pixels irregularly(randomly) for each pixel unit at the time of the high illuminance.Then, since a part of the SPAD pixels 100 among the plurality of SPADpixels 100 two-dimensionally arranged on the pixel array section 21 isthinned for each pixel unit at the time of the high illuminance, thepower consumption can be reduced.

Note that the pixel signal corresponding to the position of the thinnedpixel can be acquired by performing predetermined signal processing(e.g., correction processing), for example, on a signal processingcircuit at a latter part using the image signal acquired from the pixelssurrounding the thinned pixel.

Second Example of Driving SPAD Pixels

FIG. 2 shows a second example of driving the plurality of SPAD pixelsarranged on the pixel array section 21 of FIG. 1.

In the pixel array section 21 of FIG. 3, similar to the pixel arraysection 21 shown in FIG. 2, the plurality of SPAD pixels 100 istwo-dimensionally and regularly arranged as the R pixels, the G pixels,or the B pixels to form a Bayer array.

Also, in the pixel array section 21 of FIG. 3, a part of the SPAD pixels100 among the plurality of SPAD pixels 100 is thinned. However, thethinned pixels are arranged not for each pixel unit but for each blockunit including the plurality of pixels.

For example, in the pixel array section 21, one block is configured bythe SPAD pixels 100 having 4×4 pixels of the SPAD pixels 100 (1, 1) to100 (1, 4), the SPAD pixels 100 (2, 1) to 100 (2, 4), the SPAD pixels100 (3, 1) to 100 (3, 4), and the SPAD pixels 100 (4, 1) to 100 (4, 4).The SPAD pixels 100 in the block become the thinned pixels at the timeof the high illuminance.

In addition, for example, in the pixel array section 21, one block isconfigured by the SPAD pixels 100 having 4×4 pixels of the SPAD pixels100 (1, 5) to 100 (1, 8), the SPAD pixels 100 (2, 5) to 100 (2, 8), theSPAD pixels 100 (3, 5) to 100 (3, 8), and the SPAD pixels 100 (4, 5) to100 (4, 8). The SPAD pixels 100 in the block are general pixels andbecome any of the R pixels, the G pixels, or the B pixels even at thetime of the high illuminance.

Similarly, in the pixel array section 21, for 4×4 pixels block, a firstblock including the general SPAD pixels 100 and a second block includingthe SPAD pixels 100 that become the thinned pixels at the time of thehigh illuminance are repeated alternately in the column direction andthe row direction.

Thus, in the pixel array section 21, any SPAD pixels 100 among theplurality of SPAD pixels 100 become the thinned pixels regularly foreach block unit at the time of the high illuminance. Then, since a partof the SPAD pixels 100 among the plurality of SPAD pixels 100two-dimensionally arranged on the pixel array section 21 is thinned foreach block unit at the time of the high illuminance, the powerconsumption can be reduced.

First Example of Structure of SPAD Pixel

FIG. 4 is a cross-sectional view showing a first example of a structureof the SPAD pixel 100.

In a single photon Avalanche photodiode 110 of the SPAD pixel 100 inFIG. 4, a voltage for generating Avalanche multiplication, for example,on an anode 111 or a cathode 112. A pn junction between an n-wellreceiving the incoming light and a p+ diffusion layer causes theAvalanche multiplication to be generated.

In the single photon Avalanche photodiode 110, a transistor 121 isconnected to the anode 111. A driving signal from the control circuit 22is input to a gate of the transistor 121 to control on/off of thetransistor 121.

By the control circuit 22, if the luminance is low or medium other thanthe high illuminance, the driving signal at a predetermined level isallowed to be inputted to the gate of the transistor 121 with respect tothe SPAD pixel 100 that becomes the thinned pixel at the time of thehigh illuminance. Thus, a target SPAD pixel 100 is driven as the Rpixel, the G pixel, or the B pixel.

In addition, by the control circuit 22, if the luminance is high, thedriving signal at the predetermined level is allowed to be inputted tothe gate of the transistor 121 with respect to the SPAD pixel 100 thatbecomes the thinned pixel at the time of the high illuminance. Thus, thetarget SPAD pixel 100 becomes the thinned pixel.

Note that, by the control circuit 22, the driving signal at thepredetermined level is allowed to be inputted to the gate of thetransistor 121 with respect to the SPAD pixel 100 that becomes thegeneral pixel. Thus, irrespective of the high illuminance, the mediumilluminance, or the low illuminance, the target SPAD pixel 100 is alwaysdriven as the R pixel, the G pixel, or the B pixel.

Thus, in the SPAD pixel 100, the transistor 121 is connected to theanode 111 of the single photon Avalanche photodiode 110 and its voltageis controlled. It will be thus possible to thin a part of the SPAD pixel100 among the plurality of SPAD pixels arranged on the pixel arraysection 21 at the time of the high illuminance for each pixel unit oreach block unit.

Second Example of Structure of SPAD Pixel

FIG. 5 is a cross-sectional view showing a second example of thestructure of the SPAD pixel 100.

In the SPAD pixel 100 of FIG. 5, a transistor 122 is connected to thecathode 112 of the single photon Avalanche photodiode 110. A drivingsignal from the control circuit 22 is input to a gate of the transistor122 to control on/off of the transistor 122.

Thus, in the SPAD pixel 100, the transistor 122 is connected to thecathode 112 of the single photon Avalanche photodiode 110 and itsvoltage is controlled. It will be thus possible to thin a part of theSPAD pixel 100 among the plurality of SPAD pixels arranged on the pixelarray section 21 at the time of the high illuminance for each pixel unitor each block unit.

Third Example of Structure of SPAD Pixel

FIG. 6 is a plan view showing a third example of the structure of theSPAD pixel 100.

The SPAD pixel 100 of FIG. 6 has the structure that an Avalanche section131 that is a multiplication region of the single photon Avalanchephotodiode 110 is divided into plural and the anode 111 and the cathode112 are connected to each of the divided Avalanche section 131.

Here, the Avalanche section 131 is divided into four to form dividedAvalanche sections 131-1 to 131-4 and cathodes 112-1 to 112-4 areconnected to the respective divided Avalanche sections 131-1 to 131-4,respectively.

FIG. 7 shows a cross-sectional view taken along the line A-A′ of FIG. 6showing the third example of the structure of the SPAD pixel 100.

In the single photon Avalanche photodiode 110 of FIG. 7, the cathode112-1 is connected to the divided Avalanche section 131-1. A transistor122-1 is connected to the cathode 112-1 and an on/off operation iscontrolled in accordance with the driving signal from the controlcircuit 22.

On the other hand, a cathode 112-4 is connected to the divided Avalanchesection 131-4. A transistor 122-4 is connected to the cathode 112-4 andthe on/off operation is controlled in accordance with the driving signalfrom the control circuit 22.

By the control circuit 22, if the luminance is high, the driving signalat the predetermined level is allowed to be inputted to the gates of thetransistors 122-1 to 122-41 with respect to the SPAD pixel 100 thatbecomes the thinned pixel at the time of the high illuminance. Thus, thetarget SPAD pixel 100 becomes the thinned pixel.

At this time, in the SPAD pixel 100, the driving signal at thepredetermined level is allowed to be inputted to each of the gates ofthe transistors 122-1 to 122-4, to thereby controlling the driving foreach of the divided Avalanche sections 131-1 to 131-4.

For example, at the time of the low illuminance or the mediumilluminance, all four divided Avalanche sections of the dividedAvalanche sections 131-1 to 131-4 are used (i.e., utilization rate atthis time equals to “4/4”). However, at the high illuminance, only threedivided Avalanche sections of the divided Avalanche sections 131-1 to131-4 are used (i.e., utilization rate at this time equals to “¾”).

Note that such a thinning control for each divided Avalanche sectionunit may be performed on all of the plurality of SPAD pixels 100arranged on the pixel array section 21, or may be performed on only apart of the SPAD pixels 100.

Thus, in a case where the Avalanche section 131 of the SPAD pixel 100 isdivided into plural, the transistors 122-1 to 122-4 are connected to thecathodes 112-1 to 112-4 of the respective divided Avalanche sections131-1 to 131-4 and its voltage is controlled. It will be thus possibleto thin a part of the SPAD pixel 100 among the plurality of SPAD pixelsarranged on the pixel array section 21 at the time of the highilluminance for each divided pixel unit (divided Avalanche sectionunit).

Fourth Example of Structure of SPAD Pixel

FIG. 8 is a plan view showing a fourth example of the structure of theSPAD pixel 100.

Similar to the third example described above, the SPAD pixel 100 of FIG.8 has the structure that the Avalanche section 131 is divided into fourand the anode 111 and the cathode 112 are connected to the Avalanchesections 131-1 to 131-4.

FIG. 9 shows a cross-sectional view taken along the line A-A′ of FIG. 8showing the fourth example of the structure of the SPAD pixel 100.

In the single photon Avalanche photodiode 110 of FIG. 9, the cathode112-1 is connected to the divided Avalanche section 131-1. In addition,a gate electrode 141-1 is arranged so as to cover a part of an upperpart of the divided Avalanche section 131-1.

Here, a wiring contact is connected to the upper part of the gateelectrode 141-1. The gate electrode 141-1 performs the on/off operationin accordance with the driving signal applied via the contact such thatelectrons are transferred from the divided Avalanche section 131-1 tothe cathode 112.

An overflow drain (OFD: Overflow Drain) 142-1 is configured to becapable of discharging unnecessary electrons such that the electrons arenot leaked to the Avalanche section 131 adjacent (for example, dividedAvalanche sections 131-2 to 131-4) when the gate electrode 141-1 isturned off.

On the other hand, the cathode 112 is connected to and a gate electrode141-4 and an overflow drain 142-4 are arranged on the divided Avalanchesection 131-4. The gate electrode 141-4 performs the on/off operation inaccordance with the driving signal applied via the contact such thatelectrons are transferred from the divided Avalanche section 131-4 tothe cathode 112.

By the control circuit 22, if the luminance is high, the driving signalat the predetermined level is allowed to be applied to the gateelectrodes 141-1 to 141-4 with respect to the SPAD pixel 100 thatbecomes the thinned pixel at the time of the high illuminance. Thus, thetarget SPAD pixel 100 becomes the thinned pixel.

At this time, in the SPAD pixel 100, the driving signal at thepredetermined level is allowed to be inputted to each of the gateelectrodes 141-1 to 141-4, to thereby controlling the driving for eachof the divided Avalanche sections 131-1 to 131-4.

For example, at the time of the low illuminance or the mediumilluminance, all four divided Avalanche sections of the dividedAvalanche sections 131-1 to 131-4 are used (i.e., utilization rate atthis time equals to “4/4”). However, at the high illuminance, only onedivided Avalanche section of the divided Avalanche sections 131-1 to131-4 is used (i.e., utilization rate at this time equals to “¼”).

Note that such a thinning control for each divided Avalanche sectionunit may be performed on all of the plurality of SPAD pixels 100arranged on the pixel array section 21, or may be performed on only apart of the SPAD pixels 100.

Thus, in a case where the Avalanche section 131 of the SPAD pixel 100 isdivided into plural, the gate electrodes 141-1 to 141-4 are arrangedwith respect to the cathode 112 and the respective divided Avalanchesections 131-1 to 131-4 connected thereto and its voltage is controlled.It will be thus possible to thin a part of the SPAD pixel 100 among theplurality of SPAD pixels arranged on the pixel array section 21 at thetime of the high illuminance for each divided pixel unit (dividedAvalanche section unit).

(Example of Driving by Using Avalanche Probability)

FIG. 10 is a diagram showing an example of an Avalanche probability by avoltage difference between an anode and a cathode of the single photonAvalanche photodiode 110.

In FIG. 10, the horizontal axis represents the voltage differencebetween the anode and the cathode and the vertical axis represents theAvalanche probability.

As shown in FIG. 10, the smaller voltage difference between the anodeand the cathode is, the lower the Avalanche probability is. On the otherhand, the larger the voltage difference between the anode and thecathode is, the higher Avalanche probability is.

In other words, when the voltage difference between the anode and thecathode is sufficiently large, all electrons can generate the Avalanchemultiplication, for example. However, when the voltage differencebecomes small, the number of the electrons that generates the Avalanchemultiplication becomes about half, for example.

Here, the voltage difference between the anode and the cathode iscontrolled such that the Avalanche probability is 100% at the lowilluminance, for example. On the other hand, the voltage differencebetween the anode and the cathode is controlled such that the Avalancheprobability is decreased at the time of the high illuminance. Thus, itwill be possible to perform imaging at lower power consumption at thetime of the high illuminance.

(Flow of SPAD Pixel Driving Control Processing)

Next, with reference to a flowchart of FIG. 11, a flow of SPAD pixeldriving control processing executed by the control circuit 22 will bedescribed.

In Step S11, the control circuit 22 acquires a detection result of theilluminance.

Here, as a method of detecting the illuminance, a variety of detectionmethod can be employed. For example, the detection result of theilluminance can be acquired from an analysis result of the imageacquired from an output from an illuminance sensor or an output of thesolid-state imaging apparatus 10 (for example, whether or not image istoo bright to be saturated, etc.) or the like.

In Step S12, the control circuit 22 determines whether or not theilluminance is high by comparing the detection result of the illuminanceto the threshold value on the basis of the detection result of theilluminance acquired in the processing of Step S11.

Note that in determination processing, the detection result of theilluminance can be determined, for example, by three stages of highilluminance, medium illuminance, and low illuminance, or by two stagesof high illuminance or low illuminance depending on the threshold value.

In Step S12, in a case where it is determined it is the highilluminance, the processing proceeds to Step S13. In Step S13, thecontrol circuit 22 determines the thinned pixels.

Here, for example, the control circuit 22 determines which unit such asthe pixel unit, the block unit, and the divided Avalanche section unitthins a part of the SPAD pixels 100 among the plurality of SPAD pixels100 arranged on the pixel array section 21 on the basis of presetinformation and the like, and further determines which of the SPADpixels 100 is the actual thinned pixel.

In other words, here, it can also be said that valid SPAD pixels 100 andinvalid SPAD pixels 100 are determined respectively at the time of thehigh illuminance among the plurality of SPAD pixels 100 arranged on thepixel array section 21.

After the processing in Step S13 is ended, the processing proceeds toprocessing in Step S14. Note that in Step S12, in a case where theilluminance is determined as low or medium and not high, the processingin Step S13 is skipped, and the processing proceeds to processing inStep S14.

In Step S14, the control circuit 22 controls the driving of theplurality of SPAD pixels 100 arranged on the pixel array section 21.

Here, since the information about the unit for thinning and the thinnedpixel is determined by the processing in Step S13 at the time of thehigh illuminance, the control circuit 22 can control the driving of theplurality of SPAD pixels 100 arranged on the pixel array section 21 onthe basis of the information, for example.

The flow of the SPAD pixel driving control processing has been describedabove.

In the SPAD pixel driving control processing, since it becomes possibleto thin a part of the SPAD pixels 100 among the plurality of SPAD pixels100 arranged on the pixel array section 21 at the time of the highilluminance for a predetermined unit (e.g., pixel unit, block unit, ordivided Avalanche section unit), imaging can be performed at lower powerconsumption.

<3. Modifications>

(Other Examples of Structure of SPAD Pixel)

FIG. 12 is a plan view showing other example of the structure of theSPAD pixel 100.

In the above description, it shows the structure of the Avalanchesection 131 of the SPAD pixel 100 divided into four. Any division numbermay be used by dividing the Avalanche section 131. For example, if theAvalanche section 131 is divided into two, the structure is as shown inFIG. 12.

Specifically, in FIG. 12, the Avalanche section 131 is divided into two,the divided Avalanche section 131-1 and the divided Avalanche section131-2 are formed. Here, similar to the above-described fourth example,the gate electrode 141-1 is arranged on the divided Avalanche section131-1 and the gate electrode 141-2 is arranged on the divided Avalanchesection 131-2, to thereby thinning a part of the SPAD pixels 100 foreach divided pixel unit (divided Avalanche section unit).

Note that the division number of the Avalanche section 131 isexemplified by four and two. The division number is arbitrary and may bedivided into three, eight, ten, hundred, or the like.

FIG. 13 is a plan view showing still other example of the structure ofthe SPAD pixel 100.

The above description illustrates that the Avalanche section 131 of theSPAD pixel 100 is divided into four such that region areas of thedivided Avalanche sections 131-1 to 131-4 are almost the same. However,respective region areas of the divided Avalanche sections 131-1 to 131-4may be different.

For example, as shown in FIG. 13, in the SPAD pixel 100, the dividedAvalanche section 131-1 has the largest area, and the divided Avalanchesection 131-3, the divided Avalanche section 131-2, and the dividedAvalanche section 131-4 have smaller areas in this order.

Also, here, similar to the above-described fourth example, the gateelectrode 141-1 to gate electrode 141-4 are arranged on the dividedAvalanche section 131-1 to 131-4, to thereby thinning a part of the SPADpixels 100 for each divided pixel unit (divided Avalanche section unit).

Note that, in the structures of the SPAD pixels 100 shown in FIG. 12 andFIG. 13, similar to the above-described fourth example, an overflowdrain 142 may be arranged. In addition, as the structures of the SPADpixels 100 shown in FIG. 12 and FIG. 13, similar to the third example,each of the divided Avalanche sections 131-N (N: integer of 1 or more)may be connected to different cathode 112-N.

Other Example of Driving SPAD Pixel

In the above description, when any SPAD pixels of the plurality of SPADpixels 100 in the pixel array section 21 shown in FIG. 2 irregularly(randomly) become the thinned pixels for each pixel unit at the time ofthe high illuminance, the consumption power can be reduced. Here, it isnot limited that the pixels are irregularly thinned for each pixel unitbut the pixels may be regularly thinned for each pixel unit.

According to the above description, in the pixel array section 21 shownin FIG. 3, when any SPAD pixels 100 among the plurality of SPAD pixels100 become the thinned pixels regularly for each block unit at the timeof the high illuminance, the power consumption can be reduced. Here, itis not limited that the pixels are regularly thinned for each block unitbut the pixels may be irregularly (randomly) thinned for each blockunit.

Furthermore, the number of the pixels thinned (thinned pixels) from theplurality of SPAD pixels 100 arranged on the pixel array section 21 isarbitrary at the time of the high illuminance.

Other Examples of Cross-Sectional Structure of SPAD Pixel

In the single photon Avalanche photodiode 110, an anode can be formed ata side of a first surface that is a light incident surface or at a sideof a second surface opposite to the first surface, and a cathode can beformed at a side of the second surface or a side of the first side. Inother words, the anode and the cathode of the single photon Avalanchephotodiode 110 may be arranged on surfaces of a semiconductor or may bearranged on a front surface and a rear surface, for example.

Other Examples of Sensor

The above description illustrates an image sensor (for example, CMOS(Complementary Metal Oxide Semiconductor) image sensor) for acquiringimage data as the solid-state imaging apparatus 10. However, it may beused as other sensor such as a distance sensor (for example, sensor ofmeasuring distance by TOF (Time of Flight) method).

Other Examples of Arrangement Pattern of SPAD Pixel

In the above description, the Bayer array is illustrated as thearrangement pattern of the plurality of SPAD pixels 100 arranged on thepixel array section 21. However, other arrangement patterns may beemployed. In addition, it illustrates that the SPAD pixels 100 are the Rpixels, the G pixels, or the B pixels. However, for example, it mayinclude W pixels of white (W), IR pixels of infrared rays (IR), or thelike.

Other Examples of Control Circuit

The above-description illustrates that the control circuit 22 controlsthe driving of the plurality of SPAD pixels 100 arranged on the pixelarray section 21. However, an external device different from thesolid-state imaging apparatus 10 may control the driving of the SPADpixels 100. Thus, other measures may control the driving of the SPADpixels 100.

<4. Configuration of Electronic Device>

FIG. 14 is a block diagram showing a configuration example of anelectronic device including the solid-state imaging apparatus to whichthe present technology is applied.

The electronic device 1000 is an imaging device such as a digital stillcamera and a video camera, a mobile terminal device such as a smartphoneand a tablet type terminal, and the like.

The electronic device 1000 includes a solid-state imaging apparatus1001, a DSP circuit 1002, a frame memory 1003, a display section 1004, arecording section 1005, an operating section 1006, and a power supplysection 1007. In addition, in the electronic device 1000, the DSPcircuit 1002, the frame memory 1003, the display section 1004, therecording section 1005, the operating section 1006, and the power supplysection 1007 are connected each other via a bus line 1008.

The solid-state imaging apparatus 1001 corresponds to theabove-described solid-state imaging apparatus 10 (FIG. 1), the structureof the plurality of SPAD pixels two-dimensionally arranged on the pixelarray section 21 (FIG. 1) employs the above-described structures (forexample, first to fourth examples of structures of SPAD pixels 100), anddriving thereof can be controlled by the above-described driving (forexample, first example to second example of driving SPAD pixels 100).

The DSP circuit 1002 is a camera signal processing circuit that processa signal fed from the solid-state imaging apparatus 1001. The DSPcircuit 1002 outputs image data acquired by processing the signal fromthe solid-state imaging apparatus 1001. The frame memory 1003temporarily holds the image data processed by the DSP circuit 1002 foreach frame unit.

The display section 1004 includes a panel type display device such as aliquid crystal panel and an organic EL (Electro Luminescence) panel, anddisplays moving images or still images imaged by the solid-state imagingapparatus 1001. The recording section 1005 records the image data of themoving images or the still images imaged by the solid-state imagingapparatus 1001 on a recording medium such as a semiconductor memory anda hard disc.

The operating section 1006 outputs operation commands concerning avariety of functions included in the electronic device 1000 inaccordance with an operation by a user. The power supply section 1007feeds a variety of power sources for operating power sources of the DSPcircuit 1002, the frame memory 1003, the display section 1004, therecording section 1005, and the operating section 1006 to objects to befed, as appropriate.

The electronic device 1000 is configured as described above. The presenttechnology is applied to the solid-state imaging apparatus 1001 asdescribed above. Specifically, the solid-state imaging apparatus 10(FIG. 1) is applicable to the solid-state imaging apparatus 1001. Byapplying the present technology to the solid-state imaging apparatus1001, since a part of the SPAD pixels 100 among the plurality of SPADpixels 100 arranged on the pixel array section 21 is thinned at the timeof the high illuminance for a predetermined unit (e.g., pixel unit,block unit, or divided Avalanche section unit), imaging can be performedat lower power consumption.

<5. Usage Example of Solid-State Imaging Apparatus>

FIG. 15 is a diagram showing a usage example of the solid-state imagingapparatus to which the present technology is applied.

The solid-state imaging apparatus 10 (FIG. 1) can be used in variouscases of sensing light such as visible light, infrared light,ultraviolet light, and X-rays as follows. Specifically, as shown in FIG.15, solid-state imaging apparatus 10 can be used in apparatuses not onlyin the field of viewing in which images to be viewed are photographed,but also, for example, in the field of traffics, the field of homeelectronics, the field of medical, health-care, the field of security,the field of beauty care, the field of sports, the field of agriculture,or the like.

Specifically, in the field of viewing, for example, the solid-stateimaging apparatus 10 can be used in an apparatus of photographing theimages to be viewed (for example, electronic device 1000 of FIG. 14)such as a digital camera, a smartphone, and a mobile phone with a camerafunction.

In the field of traffics, for example, the solid-state imaging apparatus10 can be used in an apparatus used for traffic purposes such as acar-mounted sensor that photographs front/rear/periphery/inside of anautomobile, a surveillance camera that monitors running vehicles androads, and a distance measurement sensor that measures distances amongvehicles, for safe driving including automatic stop, recognition of adriver's state, and the like.

In the field of home electronics, for example, the solid-state imagingapparatus 10 can be used in an apparatus used in home electronics suchas a TV, a refrigerator, and an air conditioner, for photographinggestures of users and executing apparatus operations according to thegestures. In addition, in the field of medical and health-care, forexample, the solid-state imaging apparatus 10 can be used an apparatusused for medical and health-care purposes, such as an endoscope and anapparatus that performs blood vessel photographing by receiving infraredlight.

In the field of security, for example, the solid-state imaging apparatus10 can be used in an apparatus used for security purposes, such as asurveillance camera for crime-prevention purposes and a camera forperson authentication purposes. In the field of beauty care, forexample, the solid-state imaging apparatus 10 can be used in anapparatus used for beauty care purposes, such as a skin measurementapparatus that photographs skins and a microscope that photographsscalps.

In the field of sports, for example, the solid-state imaging apparatus10 can be used in an apparatus used for sports purposes, such as anaction camera and a wearable camera for sports purposes. In addition, inthe field of agriculture, for example, the solid-state imaging apparatus10 can be used in an apparatus for agriculture purposes, such as acamera for monitoring a state of fields and crops

<6. Application Example for Mobile Body>

The technology of the present disclosure (the present technology) can beapplied to a variety of products. For example, the technology of thepresent disclosure may be realized as a device included in any type of amobile body such as an automobile, an electric automobile, a hybridelectric automobile, a motorcycle, a bicycle, personal mobility, anairplane, a drone, a ship, a robot, and the like.

FIG. 16 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 16, the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 16, anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 17 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 17, the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 17 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

As above, an example of the vehicle control system to which thetechnology according to the present disclosure is applicable isdescribed. The technology according to the present disclosure isapplicable to the imaging section 12031 of the above-describedconfigurations. Specifically, the solid-state imaging apparatus 10 ofFIG. 1 is applicable to the imaging section 12031. By applying thetechnology according to the present disclosure to the imaging section12031, since a part of the SPAD pixels among the plurality of SPADpixels arranged on the pixel array section is thinned at the time of thehigh illuminance for a predetermined unit (e.g., pixel unit, block unit,or divided Avalanche section unit), imaging can be performed at lowerpower consumption.

Note that the embodiments of the present technology are not limited tothe above-described embodiments. Various modifications and alterationsof the present technology may be available without departing from thespirit and scope of the present disclosure.

In addition, the present technology may have the following structures.

(1)

A solid-state imaging apparatus, including:

a pixel array section on which a plurality of SPAD (Single PhotonAvalanche Diode) pixels is two-dimensionally arranged, in which

in a case where illuminance becomes first illuminance higher thanreference illuminance, a part of the SPAD pixels of the plurality ofpixels arranged on the pixel array section is thinned.

(2)

The solid-state imaging apparatus according to (1), in which

in the pixel array section, thinned pixels being the part of the SPADpixels are thinned for a pixel unit or a block unit including theplurality of pixels.

(3)

The solid-state imaging apparatus according to (2), in which

the thinned pixels are arranged regularly or irregularly on the pixelarray section for the pixel unit or the block unit.

(4) The solid-state imaging apparatus according to (1) or (2), in which

the thinned pixels are thinned by controlling a voltage of an anode or acathode of each SPAD.

(5)

The solid-state imaging apparatus according to (1), in which

the SPAD pixels have a plurality of divided Avalanche sections of theSPADs and are thinned for each divided Avalanche section unit of thedivided Avalanche sections.

(6)

The solid-state imaging apparatus according to (5), in which

each divided Avalanche section is thinned by controlling a voltage of ananode or a cathode.

(7)

The solid-state imaging apparatus according to (5), in which

each divided Avalanche section is thinned by controlling a gateelectrode arranged at an upper part of the divided Avalanche section.

(8)

The solid-state imaging apparatus according to (7), further including:

an overflow drain for discharging unnecessary electrons for each dividedAvalanche section.

(9)

The solid-state imaging apparatus according to any of (1) to (8), inwhich

a potential difference between the anode and the cathode of the SPAD iscontrolled for each thinned pixel of the part of the SPAD pixels byusing a relationship to an Avalanche probability.

(10)

The solid-state imaging apparatus according to any of (1) to (9), inwhich

the illuminance is classified into a plurality of stages including thefirst illuminance depending on a reference threshold value.

(11)

The solid-state imaging apparatus according to (10), in which

the illuminance is classified into two stages of the first illuminanceand a second illuminance lower than the first illuminance depending onthe threshold value.

(12)

The solid-state imaging apparatus according to (10), in which

the illuminance is classified into three stages of the firstilluminance, a second illuminance lower than the first illuminance, anda third illuminance lower than the second illuminance depending on thethreshold value.

(13)

The solid-state imaging apparatus according to any of (1) to (12), inwhich

in the SPAD of the SPAD pixels,

-   -   an anode is formed at a side of a first surface that is a light        incident surface or at a side of a second surface opposite to        the first surface, and    -   a cathode is formed at a side of the second surface or a side of        the first side.        (14) A driving method of a solid-state imaging apparatus        including a pixel array section on which a plurality of SPAD        pixels is two-dimensionally arranged, including:

in a case where illuminance becomes first illuminance higher thanreference illuminance, thinning a part of the SPAD pixels of theplurality of pixels arranged on the pixel array section.

REFERENCE SIGNS LIST

-   10 solid-state imaging apparatus-   21 the pixel array section-   22 control circuit-   23 readout circuit-   100 SPAD pixel-   110 single photon Avalanche photodiode (SPAD)-   111 anode-   112, 112-1 to 112-4 cathode-   121 transistor-   122 transistor-   131 Avalanche section-   131-1 to 131-4 divided Avalanche section-   141-1 to 141-4 gate electrode-   142-1 to 142-4 overflow drain-   1000 electronic device-   1001 solid-state imaging apparatus-   12031 imaging section

The invention claimed is:
 1. A light detecting device, comprising: aplurality of avalanche photodiodes arranged in a two-dimensional array,including a first avalanche photodiode and a second avalanchephotodiode; a first transistor coupled to an anode or a cathode of thefirst avalanche photodiode; and a second transistor coupled to an anodeor a cathode of the second avalanche photodiode, wherein, in a firstmode, the first transistor is in an ON state and the second transistoris in an ON state, wherein, in a second mode, the first transistor is inthe ON state and the second transistor is in an OFF state, wherein theplurality of avalanche photodiodes are disposed at a side of a firstsurface of a semiconductor substrate that is a light incident surface,and the anode or the cathode of the first avalanche photodiode and theanode or the cathode of the second avalanche photodiode are disposed ata side of a second surface opposite to the first surface, and whereinthe light detecting device is configured to switch between the firstmode and the second mode according to an amount of incident light. 2.The light detecting device according to claim 1, wherein the lightdetecting device is configured to switch from the first mode to thesecond mode in a case where the amount of incident light exceeds apredetermined threshold.
 3. A light detecting device comprising: aplurality of avalanche photodiodes arranged in a two-dimensional array,including a first avalanche photodiode and a second avalanchephotodiode; a first transistor coupled to an anode or a cathode of thefirst avalanche photodiode; and a second transistor coupled to an anodeor a cathode of the second avalanche photodiode, wherein, in a firstmode, the first transistor is in an ON state and the second transistoris in an ON state, wherein, in a second mode, the first transistor is inthe ON state and the second transistor is in an OFF state, wherein theplurality of avalanche photodiodes are disposed at a side of a firstsurface of a semiconductor substrate that is a light incident surface,and the anode or the cathode of the first avalanche photodiode and theanode or the cathode of the second avalanche photodiode are disposed ata side of a second surface opposite to the first surface, wherein, in athird mode, the first transistor is in an OFF state and the secondtransistor is in the OFF state, wherein the light detecting device isconfigured to switch from the first mode to the second mode in a casewhere the amount of incident light exceeds a first predeterminedthreshold, and wherein the light detecting device is configured toswitch from the second mode to the third mode in a case where the amountof incident light exceeds a second predetermined threshold larger thanthe first predetermined threshold.
 4. The light detecting device,comprising: a plurality of avalanche photodiodes arranged in atwo-dimensional array, including a first avalanche photodiode and asecond avalanche photodiode; a first transistor coupled to an anode or acathode of the first avalanche photodiode; and a second transistorcoupled to an anode or a cathode of the second avalanche photodiode,wherein, in a first mode, the first transistor is in an ON state and thesecond transistor is in an ON state, wherein, in a second mode, thefirst transistor is in the ON state and the second transistor is in anOFF state, wherein the plurality of avalanche photodiodes are disposedat a side of a first surface of a semiconductor substrate that is alight incident surface, and the anode or the cathode of the firstavalanche photodiode and the anode or the cathode of the secondavalanche photodiode are disposed at a side of a second surface oppositeto the first surface, wherein the two-dimensional array includes a firstblock having an n=n subset of the plurality of avalanche photodiodesincluding the first avalanche photodiode, and a second block having anm=m subset of the plurality of avalanche photodiodes including thesecond avalanche photodiode, and wherein n and m are integers greaterthan one.
 5. The light detecting device according to claim 1, whereinthe anode or the cathode of the first avalanche photodiode and the anodeor the cathode of the second avalanche photodiode are constituted by ashared electrode.
 6. The light detecting device according to claim 1,further comprising a control circuit configured to output a signal to agate of the second transistor, thereby to switch the second transistorbetween the ON state and the OFF state.
 7. The light detecting deviceaccording to claim 6, wherein the control circuit is configured todetermine whether an amount of incident light exceeds a predeterminedthreshold.
 8. The light detecting device according to claim 7, furthercomprising: an illuminance sensor configured to detect the amount ofincident light, wherein the control circuit is configured to determinewhether the amount of incident light exceeds the predetermined thresholdbased on an output of the illuminance sensor.
 9. The light detectingdevice according to claim 7, wherein the control circuit is configuredto determine whether the amount of incident light exceeds thepredetermined threshold based on an output image of the light detectingdevice.
 10. The light detecting device according to claim 1, furthercomprising a color filter array disposed over the plurality of avalanchephotodiodes.
 11. The light detecting device according to claim 10,wherein the color filter array includes red color filters, blue colorfilters, and green color filters arranged in a Bayer arrangementpattern.
 12. A distance sensor comprising the light detecting deviceaccording to claim 1, wherein the distance sensor is configured tomeasure a distance based on a time of flight method.
 13. A distancesensor comprising the light detecting device according to claim 3,wherein the distance sensor is configured to measure a distance based ona time of flight method.
 14. A distance sensor comprising the lightdetecting device according to claim 4, wherein the distance sensor isconfigured to measure a distance based on a time of flight method.